<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <!-- <link rel="stylesheet" href="test.css"> -->
</head>
<body>
    <style>
        /* p {
            color: red;
            font-size: 30px;
        } */
        /* .red {
            color:red;
        }
        .font {
            font-size: 40px;
        }
        #green {
            color: green;
        } */
        /* * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        } */
    </style>
    <p id="green">
        hello
    </p>
    <p>
        world
    </p>
    <!-- <p class="red">
        world
    </p>
    <p class="red font">
        hello
    </p> -->

</body>
</html>